Multiple choice

5 men or 12 boys can do a piece of work in 39 days. How many days will be taken by 16 men and 24 boys to do a work, which is double the original work?

  1. 12

  2. 15

  3. 17

  4. 20
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

5 men = 12 boys. 16 men + 24 boys = (16 * 12/5) + 24 boys = 38.4 + 24 = 62.4 boys. 12 boys take 39 days for 1 unit of work. 62.4 boys take (12 * 39) / 62.4 = 7.5 days for 1 unit. For 2 units, it takes 7.5 * 2 = 15 days.

AI explanation

Given 5 men equal 12 boys, the total work is equivalent to 5 men times 39 days, or 195 man-days. The combined team has 16 men and 24 boys, and converting the boys to men gives 24 divided by 12 times 5, which is 10 men; adding the 16 men gives a total of 26 men. Since the new work is double, it requires 390 man-days. Dividing 390 man-days by 26 men results in 15 days.

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